Field of the Invention
The present invention generally relates to a linear vibrator for transmitting tactile signals to a user of a mobile phone, PDA, or a portable game console. More particularly, the present invention relates to a linear vibrator using rubber or silicone rubber having lower elasticity as a material of an elastic body secured to a casing or a base for supporting an oscillator horizontally moving by an electromagnetic force relative to a facing stator, thereby lowering the frequency sensitivity due to a characteristic frequency; reducing various errors of parts and errors in part assembly, thus resulting in smaller deviations of characteristic frequencies between products from mass production; and significantly reducing production cost by using an elastic body made of rubber or silicon rubber instead of steel plate or wire, thereby efficiently producing a structure through a simple assembly process and reducing the manufacture facility cost and labor cost resulting in improved productivity.
Description of the Related Art
For transmitting tactile signals to a user of a mobile phone, PDA, or a portable game console by generating vibration, a rotating device using an eccentric mass has conventionally been used. More recently, a linear vibrator has been developed for maximizing the vibrating intensity by making the exciting frequency coincide with the characteristic frequency of a structure.
Recently developed linear vibration generators or linear vibrators with thin structures, which provide horizontal vibrations of high intensities, have been proposed, for example, through Korean Patent Applications No. 10-2010-0090230, 10-2011-0008308, 10-2011-0019823, 10-2012-0124255, and 10-2013-0089911 filed by the same applicant as the present invention.
Such linear vibrators conventionally comprise an oscillator having a weight installed inside of a casing, and an elastic metal body formed in a U-shaped structure surrounding the weight, one end of which is connected to the weight and the other end of which is secured to the casing. Such a vibrator generates horizontal vibration by use of a resonance formed by applying an electromagnetic force of exiting frequency at the same frequency as the characteristic frequency of the elastic body, in which the vibration is maximized when the excited frequency of the electromagnetic force coincides with the characteristic frequency of the elastic body.
The elastic body, however, comprises a leaf spring formed of a steel plate or a coil spring formed of a steel wire, and the characteristic frequency may be easily changed by a trivial difference such as an insignificant shape difference between products, so that it is difficult to make the exciting frequency coincide with an intended characteristic frequency,
This makes the mass production of elastic bodies having constant features such as a constant characteristic frequency, difficult and thus requires high production cost.
The description provided above as a related art of the present invention is only for helping understanding the background of the present invention and should not be construed as being included in the related art known by those skilled in the art.